BIOM 121 1nd EditionExam # 1 Study Guide LecturesNon-vascular seedless plants (like mosses), evolved first, then vascular seedless (ferns), and then vascular seed plants (gymnosperms and angiosperms).Plants have grown to become more independent from water. One way that they have done this is to develop a waxy cuticle that prevents water loss. This cuticle surrounds epidermal and endodermal layers.Haploid-1 set of chromosomes, diploid-2 sets, triploid-3 setsAlternation of generations- Plants have a 1n and 2n stage. The 1n plant is called a gametophyte. The 2n plant is called a sporophyte. - The 2n sporophyte undergoes meiosis to create 1n spores. These spores undergo mitosisto become a 1n gametophyte. The 1n gametophyte then undergoes mitosis to create 1n gametes. These 1n gametes get fertilized and this creates a 2n zygote. The zygote undergoes mitosis to become a 2n sporophyte.Nonvascular seedless- Mosses and liverworts- These plants do not have vasculature (vessels or roots) or seeds.- Due to this, they have restricted environments that they can live in. They must live in moist areas. They also cannot grow very tall, up to a few inches. - The sporophyte is completely dependent on the gametophyte. - For reproduction, water is necessary because the sperm need to swim to the egg for fertilization to occur. Vascular seedless- These plants have vessels so this allows them to grow much taller than the mosses. However, they still do not have seeds.- The sporophyte and the gametophyte are independent of one another. Spores can travela long way because they are carried by wind.- Since they are seedless, they still need water to get the sperm to the egg. This occurs on the heart-shaped gametophyte.Vascular seed plants- Contain vasculature for movement of water and other compounds- Use seeds for reproductiono These seeds are dormant, embryonic sporophytes. They are protected by a hard outer covering called a seed coat. Inside is the endosperm which provides nutrients for the growing baby plant.- The gametophyte is dependent on the sporophyte.- There are 2 types of seed plants, angiosperms (flowering fruit producing plants) and gymnosperms (“naked seed”).o Gymnosperms-reproductive structures are the cones. There are female and male cones. Male cones produce pollen (an adult male plant). Produce a lot of pollen because it is spread by windo Angiosperms-reproduction occurs through double fertilization. Produces a little pollen because it is carried directly to other plants by bugs- 2 organ systems-roots and shootso Shoots-stems and leaves, do photosynthesis Contains nodes-the places where the leaf attaches to the stemo Roots-uptake water and minerals, anchor plant- Dermal tissueo Epidermis-top most tissue-made of waxy cuticle (prevents water loss and infection)o Periderm-produces bark (only in woody plants)o Parenchyma-perform photosynthesis and storage-livingo Collenchyma-living-support-have thickened cell wallso Sclerenchyma-die at maturity-component of wood- Vasculatureo Xylem-dead-move water and minerals, supporto Phloem-live-move sugars- Stomatao Pores that allow for water loss and gas entryo Surrounded by guard cells- Plant growtho Primary-upwardo Secondary-lateral, only in woody plantso Meristems-“stem cells” Apical-at tips Lateral-new xylem and phloemOsmosis and diffusion- Diffusion-movement of solute from a high concentration of that solute to a low concentration of that solute- Osmosis-movement of water from a high concentration of water to a low concentration of water- Water moves through aquaporins that are imbedded in the membrane.Roots- Endodermis surrounds vascular cylinder that are sealed with wax- Vascular cylinder contains xylem and phloem. X=xylem, phloem surrounds in- The wax prevents unwanted water loss. - Minerals that plants need-K+, Ca2+, nitrate (NO3-), phosphate (PO4 3-)- Mineral concentration is higher inside root than outside root.- Plants pump minerals in so that water follows. These pumps are in the endodermal cells.Water movement- Living cells are not needed.- Leaves are required.- Water is pulled up, not pushed, by negative pressure- This process is called transpiration.o This is caused by evaporation from the leaves via the stomata.o As the water is pulled up the leaves, the water molecules stick together (cohesion) and they also stick to the walls of the xylem (adhesion). These forces create tension which allows the water molecules to be pulled up out of the roots,through the xylem, and out of the leaves.Phloem- Transports sugars any direction through living tubes- Uses energy to pump the sugars (positive pressure)- Moves sugar from source (leaves) to sink (fruit)- Requires living cells, atp, moves in any direction, positive pressure does it- Stepso Photosynthesis makes sugars in the leaveso Leaves pump the sugar into the phloemo Water follows the solute from xylem to phloem by osmosiso This causes pressure to build up and pushes the sapo The sugar arrives at the sink and the sink pumps the sugar from the phloem into itself leaving the water behind in the phloem.o The sugar has lost all the solute which makes it less concentrated than the water in the xylem (which contains minerals). o This causes the water to leave the phloem and enter the xylem.HormonesEthylene- Is released when the plant in under stress (wound, drought, temperature change)- Gaseous form- Causes ripening of fruit- Used frequently in the agriculture industry- Produced in all parts of the plant- Also causes tissue death (ex: leaves falling off in autumn)o When in stress, the extraneous material is the first to goAbscisic acid- Stress hormone- Plays a role in keeping the seeds and buds dormant- Roots produce this hormone when they sense a lack of water- This causes the stomata to close so to prevent water loss via transpiration.- It also inhibits growth- This also stops photosynthesis since CO2 can’t enter the stomataGibberellin- Steroid hormone-can pass through cell membranes- Causes growth of the plant by elongating cells between nodes- Produced in the seed but can be produced elsewhere too- Causes enlargement of the fruit as well- Therefore, seedless plants have smaller fruits- Can be used in the ag industry to enhance fruitAuxins- Also controls growth by elongating cells, this growth is directional- Produced by the apical meristems (located at the